Re: [ATM] Why Lurie-Houghton telescope very rare in the ATM or market?

[aki.lotjonen@phnet.fi]

Hi all,

I have read that ppl have had some kind of thermal problems with LHN telescope's
corrector cell and lenses. Rear lens is cooling down slower than the front one.
I have tested my telescope just a few times in cold weather so hard to say for
sure what was the cooling down time compared to similar oridinary Newton...
Well, the nights are coming darker over here in Finland, so have to make notes
of cooling down times.
Anyway, maybe that is one reason and there really is a lot of work with a LHN
optics, isn't it? Otherwise I think LHN telescope is just great.

Rgds,
Aki Lötjönen
http://koti.phnet.fi/lottaki




> I had the same question. Nagesh Kanvindeh and I are
> making a L-H right now, so that will make four of
> them.
> Guy
>
> --- Ukyo Chen <ukyochen888@hotmail.com> wrote:
>
> > Dear all,
> >
> > Lurie-Houghton telescope use convex & concave lenses
> > combination to correct
> > sphere mirror, it do perform a good image (diffract
> > limit) compares wit
> > Newtonian, Schmidt-Newtonian and Maksutov-Newtonian.
> > Also L-H telescope has
> > wide tolerance in surface radius, lens distance, all
> > surfaces are smooth
> > sphere. It only get a little distortion at the field
> > edge.
> >
> > Just wonder why seldom ATMer or factory like to make
> > this type of telescope.
> > I only know Rick Scott, Roger Ceragioli and Aki
> > Lötjönen had made their L-H
> > telescopes.
> >
> > Best Regards,
> > Ukyo Chen
> >
> >
> > _______________________________________________
> > ATM mailing list http://www.atmlist.net/
> >
>
>
> Guy  Brandenburg
> Washington, DC
> My home page:
> http://home.earthlink.net/~gfbranden/GFB_Home_Page.html
> _______________________________________________
> ATM mailing list http://www.atmlist.net/
>


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